1. Field of the Invention
This invention relates to a method for enhancing UV tanning of skin using liposomes and, in particular, liposomes containing one or more DNA repair enzymes (hereinafter referred to as "DNA repair liposomes").
2. Description of the Prior Art
Tanning is the natural response of human and animal skin to exposure to UV radiation and involves enhanced production and distribution by melanocytes of the protein melanin in the skin. Biochemically, melanin is produced by polymerization of oxidation products of tyrosine and dihydroxyphenyl compounds, e.g., dopa.
Tanning has both a cosmetic and clinical value. Cosmetically, tanned skinned is considered desirable by many people as evidenced by the widespread use of tanning lotions, tanning parlors, and the popularity of recreational sunbathing. Clinically, tanned skin is more resistant to the deleterious effects of sunlight than untanned skin. For example, people with more pigmented skin tend to suffer a lower incidence of skin cancer.
In view of these facts, there have been continuing efforts to develop methods and materials which will enhance tanning. The ideal tanning system would be one which both increases the tanning response and decreases the deleterious effects of sun exposure. The present invention is directed to providing such a system.